Experimental Study of the Effect of Impeller Geometrical Parameters on Fluid Hydrodynamics in Copper Solvent Extraction Mixer

ADMT Journal

مقاله 3، دوره 10، شماره 4، اسفند 2017، صفحه 21-25   

نوع مقاله: Original Article

نویسندگان

S. Parvizi^{* 1}؛ S. Aosati²؛ E. Keshavarz Alamdari³

¹Assistant Professor, Faculty of Mechanical Engineering, Shahid Rajaee Teacher Training University (SRTTU)

²MSc, Department of Mining and Metallurgical Engineering, AmairKabir University of Technology (Tehran Polytechnic)

³Associate Professor, Department of Mining and Metallurgical Engineering, AmairKabir University of Technology (Tehran Polytechnic)

چکیده

Dynamic mixers are widely used in hydrometallurgical processes. Improvement in mixers’ efficiency is one of the greatest challenges in this research.The geometrical factors of the impeller are of the most important elements affecting hydrodynamics and efficiency. Type, diameter, speed and off-bottom clearance of impeller are investigated in this work. These factors are validated by experimental setup. Mixing time is assumed fixed. Materials composition is set according to solvent extraction unit of Sarcheshmeh copper complex, Iran. The setup is manufactured according to the mixer dimensions in industrial unit. The hydrodynamic behavior of mixture is visualized by using an advanced imaging and lighting system. The effect of impeller speed in the range of 75 to 275 rpm on the position of eddies and fluid hydrodynamics are investigated. According to the results, at impeller speeds more than 200 rpm dead zones around the baffles are intend to be vanished. Furthermore, the effect of off-bottom clearance on hydrodynamics is studied. Optimum clearance to tank diameter ratio are determined 0.4 and 0.33 for 100 and 200 rpm, respectively. Results shows Rushton impeller with 6 vertical blades and impeller to tank diameter of 0.33 is optimum.

کلیدواژه‌ها

Dynamic mixer؛ Hydrodynamics؛ Impeller geometry؛ Impeller speed؛ Off-bottom clearance؛ Solvent extraction

مراجع

[1]     Kraume, M., Gäbler, A., and Schulze, K., “Influence of Physical Properties on Drop Size Distribution of Stirred Liquid‐Liquid Dispersions”, Chemical Engineering & Technology, Vol. 27, 2004, pp. 330-334.

[2]     Mersmann, A., “Fluid Dynamics of Fluid Two Phase Systems”, In Preprints 5th International Congress of Chemical Engineering, CHUSA 75, Prague, Czech-Republic, 1975.

[3]     Shabani, M. O., Mazahery, A., “Computational Fluid       Dynamics (CFD) Simulation of Liquid-Liquid Mixing in Mixer-Settler”, Archive of Metallurgy and Materials, Vol. 57, 2012, pp. 173-178.

[4]     Parvizi, S., Keshavarz Alamdari, E., Hashemabadi, S. H., Kavousi, M., and Sattari, A., “Investigating Factors Affecting on the Efficiency of Dynamic Mixers”, Mineral Processing and Extractive Metallurgy Review, Vol. 37, 2016, pp. 342-368.

[5]     Paul, E. L., Atiemo-Obeng, V. A., Kresta, and S. M., Handbook of Industrial Mixing: Science and Practice, John Wiley & Sons, 2004.

[6]     Shabani, M. O., Alizade, M., and Mazahery, A., “Fluid Flow Characterization of Liquid-Liquid Mixing in Mixer-Settler”, Engineering with Computers, Vol. 27, 2011, pp. 373-379.

[7]     Abu-Farah, L., Al-Qaessi, F., and Schonbucher, A., “Cyclohexan /Water Dispersion Behavior in Stirred Batch Vessel Experimentally and with CFD Simulation”, Procedia Computer Science, Vol. 1, 2012, pp. 655-664.

[8]     Zhao, Y. C., Li, X. Y., Chen, J. C., Yang, C., and Mao, Z. S., “Experimentl Study on Liquid-Liquid MAcro-Mixing in a Stirred Tank”, Industrial Engineering Chemical Research, Vol. 50, No. 10, 2011, pp. 5952-5958.

[9]     Rewatkar, V., Joshi, J., “Effect of Impeller Design on Liquid Phase Mixing in Mechanically Agitated Reactors”, Chemical Engineering Communication, Vol. 102, 1991, pp. 1-33.

[10]  Pandit, A., Joshi, J., “Mixing in Mechanically Agitated Gas-Liquid Contactors, Bubble Columns and Modified Bubble Columns”, Chemical Engineering Science, Vol. 38, 1983, pp. 1189-1215.

[11]  Raghav Rao, K., Joshi, J., “Liquid Phase Mixing in Mechanically Agitated Vessels”, Chemical Engineering Communications, Vol. 74, 1988, pp. 1-25.

[12]  Zhou, G., Kresta, S. M., “Impact of Tank Geometry on the Maximum Turbulence Energy Dissipation Rate for Impellers”, AICHE J., Vol. 42, 1996, pp. 2476-2490.

[13]  Cheng, D., Feng, X., Cheng, J. C., and Yang, C., “Numerical Simulation of Macro Mixing in Liquid-Liquid Stirred Tank”, Chemical Engineering Science, Vol. 101, 2013, pp. 272-282.

[14]  Jaworski, Z., Nienow, A., and Dyster, K., “An LDA Study of the Turbulent Flow Field in a Baffled Vessel Agitated by an Axial, Down‐Pumping Hydrofoil Pmpeller”, The Canadian Journal of Chemical Engineering, Vol. 74, 1996, pp. 3-15.

[15]  Mavros, P., Xuereb, C., and Bertrand, J., “Determination of 3-D Flow Fields in Agitated Vessels by Laser-Doppler Velocimetry: use and Interpretation of RMS Velocities”, Chemical Engineering Research Design, Vol. 76, 1998, pp. 223-233.

[16]  Shabani, M., Mazahery, A., “Evaluation of the Effect of Mixer Settler Baffles on Liquid-Liquid Extraction Via CFD Simulation”, UPB Sci Bull Ser D, Vol. 73, 2011,   pp. 55-64.

[17]  Brůha, O., Brůha, T., Fořt, I., and Jahoda, M., “Dynamics of the Flow Pattern in a Baffled Mixing Vessel with an Axial Impeller”, Acta Polytechnica, Vol. 47, 2007,         pp. 17-26.

Fradette, L., Thomé, G., Tanguy, P. A., and Takenaka, K., “Power and Mixing Time Study Involving a Maxblend Impeller with Viscous Newtonian and Non-Newtonian Fluids”, Chemical Engineering Research Design, Vol. 85, 2007, pp. 1514-1523.